Letoff mechanism for looms



April 22, 1947. 4 o v, PAYNE v 2,419,419

LET-OFF MECHANISM FOR LOOMS Filed Sept; 8, 1945 2.Sheets-Sheet 1INVENTQR 05cm; v. PAYNE AT TORNEY P 1947- v o v PAYNE 2,419,419

LET-OFF MECHANISM FOR. LOOMS Filed Sept. 8, 1945 2 Sheets-Sheet 2.INVENTOR OSCAR V. PAYNE WWW/W17.

AT TORNEY Patented Apr. 22, 1947 2,419,419 LETOFF MECHANISM FOR LooMsOscar V. Payne, Leicester, Mass, assignor to Crompton & Knowles LoomWorks, Worcester, Mass, a corporation of Massachusetts 8, 1945, SerialNo. 615,124

Application September 7 2 Claims.

This invention relates to improvements in letoff mechanisms for loomsand it is the general object of the invention to provide means by whichthe warp beam can be manipulated without interference on the part of theweight which tensions the warp.

In a type of letoff already proposed by me the warp beam has securedthereto an arcuate guide for the chain of a weight which acts normallyto move the warp beam in a backward direction. A worm and worm gearoperate to change the angular relation of the arcuate guide with respectto the beam so that the weight will move through only a short range ofmotion as the warp thread is consumed during the weaving operation. Inthat letoff the arcuate guide is at the back of the warp beam and theweight and its chain have been located rearwardly of the loom in aposition where they project into the aisle utilized in changing the warpbeam. It is an important object of my present invention to locate thearcuate guide on the forward part of the beam structure so that theweight can be in front of its former position and not interfere with theplacing of a new warp beam into the loom.

The letoff mechanism shown in the earlier structure to which I havereferred is so constructed that the warp beam is swung angularly aroundone of its ends prior to removal of the loom. When the weight depend-sfrom the arcuate guide as in such a letoff it interferes with theangular movement of the beam and is in such position as to interferewith the workmen who are manipulating the beam. This is particularlytrue of beams of large diameter. It is another object of my presentinvention to utilize the previously employed pivotal mounting for oneend of the beam but locate the arcuate guide in such position that theweight will neither interfere with the removal of the beam nor.undergomovement as the beam is turned angularly preparatory to removal of theloom. These results I obtain by leading the weight supporting chainupwardly from the arcuate guide on the front of the beam structure andover guide pulleys moving about axes fixed with respect to the loom andthen downwardly to the weight. The latter remains more or lessstationary when the beam is being turned angularly and will not swing,thereby avoiding risk of injury to the workman.

With these and other objects in view which will appear as thedescription proceeds, my invention resides in the combination andarrangement of parts hereinafter described and. set forth.

In the accompanying drawings, wherein a convenient embodiment of myinvention is set forth,

Fig. 1 is a side elevation of a loom having my invention appliedthereto,

Fig. 2 is a rear elevation looking in the direction of arrow 2, Fig. 1

Fig. 3 is a plan view looking in the direction of arrow 3, Fig. 2,

Fig. 4 is a detail of part of the structure used with my invention,particularly that part which carries the arcuate guide,

Fig. 5 is an enlarged horizontal section on line 5-5 of Fig. 2, and

Fig. 6 shows a modified form for transmitting force from the weight tothe arcuate guide.

Referring particularly to Fig. 1, I have shown a loom frame I0 and a laysword II which reciprocates backwardly and forwardly during loomoperation. Extending rearwardly from the loom is a bracket 12 bolted toa stand l3 on the floor and having at the upper end thereof a bearingmember I4. The warp beam I5 is provided with a gudgeon I6 and supplieswarp W which passes over a whip roll H and then forwardly to the weavinginstrumentalities. The bearing [4 supports an outer ball race 18 havinga concave surface engaging ball bearings I8 which in turn engages acrowned or convex bearing ring 20 held to a sleeve 2| through which thegudgeon l6 passes.

Mounted on the sleeve 2| is a casing 25 in which turns a shaft 26carrying a worm 21 meshing with a worm wheel 28 fixed with respect tothe gudgeon l6 and turning with the warp'beam. The mechanism for turningthe shaft 25 comprises an arm 3| extending rearwardly from the lay to alever 32 pivoted as at 33 to a fixed part of the loom. The upper end oflever 32 is pivoted to a rearwardly extending connector 34 attached to arocking lever 35 pivoted on a stationary support, such as the stand 13.During loom operation reciprocation of the loom sword ll causes rockingof lever 35 and movement of its upper arm 35 toward and from the casingfor engagement with a sliding rack 31. The latter operates ratchet wheel38 which drives a clutch 39 fixed to shaft 25, causing turning of thelatter.whenever the rack is operated by the lever 35.

When the casing turns to the right as viewed in Fig. 4 the rack comeswithin the range of operation of lever 35 and a backward movement of thecasing relatively to the beam results. For further details of themechanism which controls shaft 26 see particularly Fig. 3 of my priorPatent No. 2,062,725.

The matter thus far described may be very similar to the letoifmechanisms shown in my prior patent already mentioned and also No.1,803,143.

In carrying my present invention into effect I provide an arcuate guide45 secured as at 46 to the casing 25 and grooved as at 41 to receive achain 48 the lower end of which is attached as at 49 to the arcuateguide. The chain extends upwardly from the guide to an idler pulley 50turning on a stationary stud on a stand 52 secured to the loom frame.The chain leads vertically upwardly from the idler pulley 50 to a guidepulley 53 turning on a stud 54 on a fixed stand 55. The chain is trainedaround the upper part of a guide pulley and then leads downwardly to avariable weight 5% which is located preferably in front of the axis ofthe warp beam and to one side of the loom.

. During normal loom operation the warp is consumed and rack 3'! andratchet wheel 38 periodically move the casing 25 rearwardly or in acounter-clockwise direction as viewed in Fig. 1 with respect to the beamas already set forth. The casing 25 will move through a slight range ofangular motion depending upon the extent to which the arm 36 moves thepawl .31 and the weight rises and falls during this periodic adjustmentbetween the beam and the casing 25 and constantly exerts a force on thewarp beam transmitted through the worm and the worm wheel tending toturn the warp beam in a countier-clockwise direction as viewed in Fig. 1to hold the warp W under tension.

When the exhausted warp beam is being removed from the loom there is nowarp tension to prevent weight 56 from causing counter-clockwisemovement of the beam as viewed in Fig. 1 and the casing 25 would turnbackwardly except for a ratchet Bil cast on the casing 25 in positionfor cooperation with a hold pawl 6| connected to a forwardly extendingrod {52 accessible from the front of the loom, see Fig. 4, and priorPatent No. 1,803,143. It may not be necessary in all instances to usethe ratchet Bil, since the arcuate guide 45 is so located that weight 56can rest on the floor to one side of and in front of the beam where itwill not interfere with manipulation of the beam.

That end of the beam opposite to the end shown in Fig. 1 is thendisconnected from its bearing pocket not shown and swung rearwardly, acondition which is permitted by reason of the ball bearing shown in Fig.5. During this angular movement of the beam with respect to the loom thearcuate guide 45 will move angularly with the beam, but because of theidler and guide pulleys the weight will remain in a substantially fixedposition and will not move angularly with the beam or the casing 25. Theweight will also be in a position where it will not interfere withremoval of the beam. In my previously mentioned patentsthe weight underthese conditions would have moved with the beam and there would havebeen risk of injury to the workman due to the swinging of the weight.

Fig. 6 shows a modified means of transmitting force from the weight tothe casing 25 wherein the guide pulley 53 is replaced by a lever 19moving about a pivot "H which may be the same as the axis 54 for theguide pulley 53. One end of the lever in is connected as at 12 to acable or chain 13 which extends down to the weight d5, while theopposite end of the lever is connected as at 14 to a depending chain 15connected to the arcuate guide 45. The lever ends or arms (6 and i7,respectively, are of unequal length as shown in Fig. 6 to permit the useof a smaller weight than is possible when the guide pulley 53 isemployed.

From the foregoing it will be seen that I have provided simple means bywhich a weight constantly exerts a rearward force on a warp beam but isso located as not to partake of any angular or swinging movement whenthe warp beam is swung about its ball bearing mounting shown in Fig. 5preparatory to removal from the loom. It will further be seen that theweight is located forwardly of the rear part of the warp beam andtherefore is out of the aisle behind the loom and is also in suchposition that even though it should swing slightly it will not be ableto injure the workman removing the beam. Furthermore, the lever It! hasarms of unequal length which permit the use of a lighter weight thanwhen the guide pulley 53 is used.

Having thus described my invention it will be seen that changes andmodifications may be made therein by those skilled in the art withoutdeparting from the spirit and scope of the invention and I do not wishto be limited to the detailsherein disclosed, but what I claim is:

1. In letoff mechanism for a loom having a warp beam which rotates in aforward direction to supply warp for the weaving operation, an arcuateguide extending forwardly from the warp beam and operatively connectedthereto, a guide pulley mounted on the loom frame above said arcuateguide and rotatable about an axis substantially parallel to the axis ofthe beam, a second pulley above the first pulley rotatable on the loomabout a horizontal axis substantially at right angles to the axis of thefirst pulley, said second pulley being of such diameter that one sidethereof extends beyond the end of the beam with respect to thelongitudinal center of the beam, a flexible member connected at one endthereof to the arcuate guide and extending upwardly along the firstpulley and over the second pulley and having the other end thereofdepending from said one side of said second pulley, and a weightconnected to said other end of the member, said weight effective toexert a force through the member and along said pulleys to the arcuateguide in a direction tending to cause reverse rotation of the warp beam.

2. In letofi mechanism for a warp beam rotatable about bearings one ofwhich is so constructed as to permit the warp beam to be swung angularlyrearwardly with respect to the loom about said one bearing when the beamis being removed from the loom, an arcuate guide operatively connectedto and moving with the warp beam when the latter moves angularly aboutsaid one bearing, said arcuate guide moving angularly about the axis ofthe beam during loom operation, a guide pulley above said beam rotatingabout an axis substantially parallel to the axis of the beam during loomoperation, a second pulley above the first pulley moving about ahorizontal axis substantially perpendicular to the axis of the firstpulley, a flexible member having one end connected to said arcuate guideand extending upwardly therefrom and along said pulleys and having theother end thereof depending from the second pulley, and a" weight:connected 5 6 to said other end of the member and depending TEN freelyfrom said second pulley and remaining UNITED STATES PA TS substantiallystationary during angular move- Number Name Date ment of the beamhorizontally about said one 2,169,326 Payne Aug. 15, 1939 hearing. 52,305,422 Herard Dec. 15, 1942 OSCAR V. PAYNE. 1,574,724 Zahn Feb. 23,1926 REFERENCES CITED FOREIGN PATENTS Number Country Date The followingreferences are of record in the 10 320,252 Italian Aug. 11, 1934 file ofthis patent: 659,569 French Aug. 27, 1928

